CHINESE JOURNAL OF CATALYSIS
·
2021
·Vol. 42
·期 10
·1798-1807
·
IF 8.271
Xiangyong Zhang,Tianying Liu,Ting Guo,Xueying Han,Zongyun Mu,Qiang Chen,Jiangmin Jiang,Jing Yan,Jiaren Yuan,Dezhi Wang,Zhuangzhi Wu,Zongkui Kou
Controllably mounting foreign atoms on the surfaces of earth-abundant electrocatalysts strongly improve their surface electronic properties for optimizing the catalytic performance of surficial sites to an unusual level, and provides a good platform to gain deep insights into catalytic reactions . The present work describes, employing ultrafine W 2 C nanoislands (average size: 2.3 nm) monodispersed on the N, P dual-doped carbon frameworks as a model system, how to regulate the atomic phosphorous-mounting effect on the surfaces of W 2 C to derive an active and stable P-mounting W 2 C (WCP) catalyst for both acidic and alkaline hydrogen evolution reaction (HER). Since in situ phosphorus substitution into carbon sites of preformed W 2 C nanoislands gradually proceeds from surfaces to solids, so that using a proper amount of phosphorus sources can readily control the surface mounting level to avoid the mass P-doping into the bulk. By this way, the activity per active site of WCP catalyst with robust stability can be optimized to 0.07 and 0.56 H 2 s −1 at –200 mV overpotential in acid and base, respectively, which reach up to the several-fold of pure-phase W 2 C (0.01 and 0.05 H 2 s −1 ). Theoretical investigations suggest that compared with solid P doping, the P mounting on W 2 C surface can more remarkably enhance its metallicity and decrease the hydrogen release barrier. This finding disclosed a key correlation between surface foreign atom-mounting and catalytic activity , and suggested a logical extension to other earth-abundant catalysts for various catalytic reactions .
研究领域:
材料化学
·
电催化
·
纳米材料
·
能源科学
·
表面科学
·
理论计算
✓ 已验证
DOI
高影响因子
Small
·
2020
·Vol. 16
·期 38
·2003557
·
IF 11.459
Zheng Liu,Su Zhang,Zhipeng Qiu,Chao Huangfu,Lin Wang,Tong Wei,Zhuangjun Fan
Tin (Sn) is considered to be an ideal candidate for the anode of sodium ion batteries. However, the design of Sn-based electrodes with maintained long-term stability still remains challenging due to their huge volume expansion (≈420%) and easy pulverization during cycling. Herein, a facile and versatile strategy for the synthesis of nitrogen-doped graphene quantum dot (GQD) edge-anchored Sn nanodots as the pillars into reduced graphene oxide blocks (NGQD/Sn-NG) for ultrafast and ultrastable sodium-ion storage is reported. Sn nanodots (2–5 nm) anchored at the edges of “octopus-like” GQDs via covalent Sn O C/Sn N C bonds function as the pillars that ensure fast Na-ion/electron transport across the graphene blocks. Moreover, the chemical and spatial (layered structure) confinements not only suppress Sn aggregation, but also function as physical barriers for buffering volume change upon sodiation/desodiation. Consequently, the NGQD/Sn-NG with high structural stability exhibits excellent rate performance (555 mAh g −1 at 0.1 A g −1 and 198 mAh g −1 at 10 A g −1 ) and ultra-long cycling stability (184 mAh g −1 remaining even after 2000 cycles at 5 A g −1 ). The confinement-induced synthesis together with remarkable electrochemical performances should shed light on the practical application of highly attractive tin-based anodes for next generation rechargeable sodium batteries.
研究领域:
材料科学
·
电化学
·
纳米能源
·
储能材料
·
先进电池技术
✓ 已验证
DOI
高影响因子
ChemSusChem
·
2019
·Vol. 12
·期 4
·858-865
·
IF 7.804
Xinxin Li,Qingshan Zhao,Xiang Feng,Lei Pan,Zhuangzhuang Wu,Xiaocui Wu,Tianwen Ma,Jialiang Liu,Yuanyuan Pan,Yan Song,Mingbo Wu
Graphical Nitrogen-doped graphene nanoshells supporting palladium nanoparticles (Pd/N-GNS) have been developed as a superior catalyst for the N -allylation reaction. Experimental results and DFT calculations reveal strong metal–support interactions between the pyridinic N and palladium species, which significantly boost the catalytic efficiency and stability of the catalyst. In this study, nitrogen-doped graphene nanoshells (N-GNS) were developed to support palladium nanoparticles (Pd/N-GNS) as an efficient and recyclable catalyst for the N -allylation reaction. N-GNS was synthesized through a facile hard-template method by using petroleum asphalt, followed by nitrogen doping by thermal annealing with urea, the contents and species of which could be altered by the calcination temperature. Palladium nanoparticles (Pd NPs) with an average diameter of 3.3 nm were homogeneously deposited onto the N-GNS support through a mild solvent-growth approach. The Pd/N-GNS exhibited a superior activity towards the N -allylation reaction, 6-fold higher than that of the pristine graphene nanoshells supporting the palladium catalyst. The Pd/N-GNS could be recycled several times without activity deterioration and metal leaching. The catalytic activity showed a linear correlation relationship with the pyridinic N content. Experimental and theoretical studies reveal strong metal–support interactions between the pyridinic N and palladium species, which can downsize the Pd NPs, modulate the electronic properties, and promote the adsorption of reactant, thereby significantly boosting the catalytic efficiency and stability for the N -allylation process. The present work could help unravel the roles of nitrogen-doped carbon supports and provides a feasible strategy to rationally design superior palladium catalysts for chemical transformations.
研究领域:
材料科学
·
催化化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2015
·Vol. 5
·期 108
·89290-89298
·
IF 3.84
Lili Wang,Byung Kee Moon,Sung Heum Park,Jung Hwan Kim,Jinsheng Shi,Kwang Ho Kim,Jung Hyun Jeong
A novel Sm3+-doped Sr2CaWO6 (SCWO) red phosphor, synthesized though a solid-state reaction, was reported. Its crystal structure was analyzed and refined via the Rietveld full-pattern fitting method based on XRD patterns. The CASTEP module of Materials Studio was used to investigate the band structure and density of states of the SCWO. The optical band gap was calculated through the UV-vis diffuse reflectance spectrum and compared with the value predicted by the DFT method. Raman spectra were recorded to confirm the substitution of cations by Sm3+ ions. The broad W–O charge transfer band and narrow excitation band at 406 nm from Sm3+ ions have comparable intensities in SCWO:Sm3+. After the introduction of charge compensators Li+, Na+ or K+, the intensity of the near-UV excitation band at 406 nm was almost twice as much as before. The profiles of the emission spectra under excitation into the charge transfer absorption and f–f transition of Sm3+ are different, and low-symmetry Sm3+ centres are preferentially excited via f–f absorption transitions. The intensity ratios of electronic, magnetic dipole-allowed transitions under different radiations show that the charge compensators can influence the chemical environment around Sm3+.
研究领域:
材料科学
·
固体化学
·
发光材料
·
晶体学
·
电子结构理论
·
无机功能材料
✓ 已验证
DOI
高影响因子
Journal of Energy Chemistry
·
2020
·
IF 7.216
Jinxing Yu,Xiaoxiang Xu
Cr doped Ruddlesden-Popper compound Sr 2 TiO 4 has been successfully modified by fluorine to form a new compound Sr 2 Ti 0.95 Cr 0.05 O 3 F 2 . Structure analysis suggests two types of fluorine in the structure of this new compound, i.e. intralayer and interlayer F, which induce strong built-in electric field within this layered compound. The electric field stems from uneven distribution of F atoms on the two sides of perovskite layers therefore leads to charge disproportionation . DFT calculations suggest that this unique structural feature is highly beneficial for charge dissociations as it breaks the coplanar settlement of conduction band minimum and valence band maximum whilst maintains the 2D charge transportation properties. This is clearly demonstrated by the superior photocatalytic activities of Sr 2 Ti 0.95 Cr 0.05 O 3 F 2 for hydrogen production from water. Apparent quantum efficiency (AQE) as high as 1.16% at 420 ± 20 nm has been achieved which stands as the highest AQE reported on Sr 2 TiO 4 to date. Photoelectrochemical (PEC) analysis confirms improved charge separation conditions and prolonged charge lifetime.
研究领域:
材料化学
·
光催化
·
能源化学
·
物理化学
·
无机功能材料
·
太阳能转化
·
环境科学
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2024
·
IF 9.4
Wenbin Wu,Ping Zhang,Siqi Chen,Xiaohong Liu,Guilin Feng,Meihua Zuo,Wangyan Xing,Bin Zhang,Weifeng Fan,Heng Zhang,Ping Zhang,Jie Zhang,Wei Xiang
O3 phase layered oxides are highly attractive cathode materials for sodium-ion batteries because of their high capacity and decent initial Coulombic efficiency. However, their rate capability and long cycling life are unsatisfactory due to the narrow Na + transfer channel and irreversible phase transitions of O3 phase during sodiation/desodiation process. Constructing O3/P2 multiphase structures has been proven to be an effective strategy to overcome these challenges. In this study, we synthesized bi-phasic structured O3/P2 Na(Ni 2/9 Fe 1/3 Cu 1/9 Mn 1/3 ) 1- x Mn x O 2 ( x = 0.01, 0.02, 0.03, 0.04, 0.05) materials through Mn doping during sodiation process. Benefiting from surface P2 phase layer with the enhanced Na + transfer dynamics and high structural stability , the Na(Ni 2/9 Fe 1/3 Cu 1/9 Mn 1/3 ) 0.98 Mn 0.02 O 2 (NFCM-M2) cathode delivers a reversible capacity of 139.1 mA h g −1 at 0.1 C, and retains 71.4 % of its original capacity after 300 cycles at 1 C. Our work provides useful guidance for designing multiphase cathodes and offers new insights into the structure-performance correlation for sodium-ion cathode materials.
研究领域:
材料科学
·
电化学
·
能源存储
·
无机化学
·
固态化学
✓ 已验证
DOI
高影响因子
SOLID STATE IONICS
·
2018
·
IF 2.751
Yuzhen Duan,Junming Guo,Mingwu Xiang,Jinyu Zhu,Changwei Su,Hongli Bai,Xiaofang Liu,Wei Bai,Rui Wang
A series of single crystalline spinel LiNi x Mn 2- x O 4 (0 ≤ x ≤ 0.10) cathode materials were synthesized in virtue of a facile solution-combustion approach. The morphology and the structure of all as-prepared samples were synthetically investigated with the X-ray diffraction (XRD), the scanning electron microscopy (SEM), the high-resolution transmission electron microscopy (HRTEM), and the X-ray photoelectron spectrometer (XPS). According to these investigation results, Ni-doping content has a significant impact on the control of morphology and crystalline structure, hence the as-prepared LiNi x Mn 2- x O 4 samples exhibit polyhedral morphology with high crystallinity and average size of 100–200 nm. This unique polyhedral crystal structure has numerous surfaces fitting the (111) crystalline orientation which exhibit the smallest Mn dissolution in electrolytes, whilst stabilizing the spinel framework. Owing to the merits of both single crystalline polyhedral structure and appropriate Ni-doping, the as-obtained LiNi x Mn 2- x O 4 cathodes reveal enhanced rate capability coupled with long cycling performance. In especial, the LiNi 0.08 Mn 1.92 O 4 presents a initial discharge capacity of 101.3 mAh/g and ultralong cycle stability up to 2000 cycles at 1C, whilst showing enhanced cycle performance when temperature increases to 55 °C. Excellent capacity retention of 72% and 63% is also obtained after 1000 cycles even at high current rate of 5C and 10C. This study may contribute to an effective candidate approach for the obvious improvement on lithium ion batteries in term of electrochemical activity.
研究领域:
材料科学
·
电化学
·
能源存储
·
无机化学
·
纳米材料
·
固态化学
·
电池技术
✓ 已验证
DOI
高影响因子
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
·
2017
·
IF 3.012
Y.X. Wei,Y.B. Ma,M. Chen,W.M. Liu,L. Li,Y. Yan
Electrochromic devices (ECDs) based on WO 3 and Ti doped V 2 O 5 films are fabricated by using lithium (LiClO 4 ) liquid electrolyte containing ferrocene redox couple . The addition of ferrocene in electrolyte enhances electrochromic properties of device. The device based on LiClO 4 -Ferrocene electrolyte has larger charge density than that based on LiClO 4 electrolyte. In the 600–1500 nm wavelength range, the transmittance of colored device is under 2% and it has faster coloring response. At 680 nm wavelength, it shows larger changes in transmittance from 68% to 1.8% while device based on LiClO 4 electrolyte changes transmittance from 68.3% to 11.5%. The cycling data reveal that device based on LiClO 4 -Ferrocene electrolyte can yield more stable electrochromic properties at 65 °C than room temperature. In order to deeper understand the effect of electrolyte on films and devices, electrochemical impedance spectroscopy (EIS) and the voltage distribution of films based on an analog cell are separately measured and analyzed in LiClO 4 and LiClO 4 -Ferrocene electrolytes. Results indicate that compared with LiClO 4 electrolyte, films have lower charge-transfer resistance and the distributed voltage on Ti doped V 2 O 5 film is larger in LiClO 4 -Ferrocene electrolyte, which can enhance optical properties of ECD by improving charge density of Ti doped V 2 O 5 film.
研究领域:
材料科学
·
电化学
·
功能材料
·
纳米科技
·
能源技术
✓ 已验证
DOI
高影响因子
PARTICLE & PARTICLE SYSTEMS CHARACTERIZATION
·
2023
·Vol. 40
·期 8
·2300032
·
IF 2.7
Hao Jiang,Chenxi Zang,Yixiu Dong,Min Lai,Shuhong Xu,Jingkun Xu
CsPbX 3 (X = Cl, Br, I) nanocrystals (NCs) are competitive materials for a wide range of applications because of their outstanding optoelectronic properties. Ion doping has been demonstrated as one powerful method for improving the optical properties of CsPbX 3 NCs. However, the conventional ion-doping approaches are tedious, and generally performed under an inert atmosphere and high temperature. In this work, a one-step ultrasonic-assisted approach is demonstrated to prepare doped CsPbX 3 NCs. To demonstrate the universality of the ultrasonic-assisted ion-doping approach, three ion-doped perovskite NCs are prepared, which represent three common improvements effects of ion doping on perovskite NCs, namely improved stability, PL emission, and photoluminescence quantum yields (PLQYs) of perovskite NCs. Sr-doped CsPbI 3 NCs showed improved phase stability. Mn-doped CsPbCl 3 NCs showed dual-color emissions at 406 and 580 nm. The PLQYs of the as-prepared Ni-doped CsPbCl 3 NCs are greatly improved, from 10.1% to 71%. Such a simple and versatile ion-doping approach may promote the practical applications of all-inorganic perovskite NCs.
研究领域:
材料科学
·
纳米技术
·
光电子学
·
无机化学
·
半导体材料
✓ 已验证
DOI
高影响因子
JOURNAL OF NON-CRYSTALLINE SOLIDS
·
2014
·
IF 1.716
J. Yuan,W.C. Wang,D.D. Chen,M.Y. Peng,Q.Y. Zhang,Z.H. Jiang
Enhanced 1.8 μm emission from Tm 3+ by Yb 3+ sensitization and bubbling in tungsten tellurite glasses has been demonstrated under the excitation of a 976 nm laser diode . Radiative properties such as spontaneous emission probabilities, radiative lifetimes and fluorescence branching ratios along with absorption and emission cross sections have been calculated from the absorption spectra . The influences of Yb 3+ concentration, Tm 3+ concentration, and bubbling time on spectroscopic properties have been thoroughly investigated. It is found that with increasing the bubbling time to 35 min, OH − content deceases sharply while 1.8 μm emission intensity improves greatly and 3 F 4 level lifetime prolongs to 1.57 ms close to radiative time. After 35 min, they change very little due to almost reaching the dynamic balance. The strength of interaction between Tm 3+ and OH − is determined. The energy transfer mechanism between Yb 3+ and Tm 3+ is proposed by photoemission spectroscopy and lifetime measurement. The energy transfer coefficients have been analyzed by the extended spectral overlap method and hopping model. Large ratio of the forward energy transfer from Yb 3+ to Tm 3+ to the backward one (223) and high energy transfer efficiency (97%) from Yb 3+ to Tm 3+ ensure efficient 1.8 μm emission. Hence, Yb 3+ sensitization and the reduction of OH − content could be expected to open up a possibility to achieve high efficient 2.0 μm lasing from Tm 3+ under a 976 nm LD pump.
研究领域:
光学材料
·
激光物理
·
固体激光器
·
光谱学
·
无机非金属材料
·
光子学
·
稀土发光材料
✓ 已验证
DOI
高影响因子
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
·
2014
·
IF 2.871
Hao Li,Qingni Yu,Bin Yang,Zhongjian Li,Lecheng Lei
Galvanostatic anodic oxidation of artificial human urine (AHU) was carried out by using boron doped diamond (BDD) and IrO 2 electrodes respectively. It was found that organic compounds in urine could be almost completely mineralized in a few hours and ammonia may be oxidized into N 2 by the electro-catalytic process. However, the oxidation processes were highly dependent on the electrode materials. On the non-active BDD electrode complete oxidation occurred, and the final oxidation products of inorganic ions, including ClO 4 − and NO 3 − , were formed. Whereas on the active IrO 2 electrode, the final products generated and left in solution were highly toxic substances, including N 2 H 4 and NO 2 − , because the oxidizing activity on the IrO 2 electrode surface is relatively low. The pH values during the degradation process were monitored and the corresponding degradation mechanisms and pathways on both electrodes are proposed based upon the measured inorganic intermediates.
研究领域:
环境科学
·
电化学
·
水处理技术
·
生物医学工程
·
分析化学
✓ 已验证
DOI
高影响因子
DALTON TRANSACTIONS
·
2023
·Vol. 52
·期 21
·7143-7151
·
IF 4
Lu Liang,Xiaohui Li,Xiaoge Wang,Zhaoji Luo,Kun Lin,Qiang Li,Sihao Deng,Lunhua He,Xiaojun Kuang,Xianran Xing
Mixed electronic and oxide ionic conduction was enabled in digermanate-type La2−xCaxGe2O7−x/2 containing Ge3O10 chains and isolated GeO4 units by substitution of La3+ with Ca2+. The structure and solid solution limit of Ca doped La2Ge2O7 were studied by systematic experiments, including rotation electron diffraction (RED), X-ray diffraction (XRD) and neutron powder diffraction (NPD) experiments, etc. The preferred occupation of Ca2+ and oxygen vacancies was investigated by Rietveld analysis of the NPD data. The obtained conducting material La1.925Ca0.075Ge2O6.963 exhibits superior thermal stability and an order of magnitude improvement in conductivity compared to the parent La2Ge2O7 (∼9 × 10−5 S cm−1 at 1000 °C). BVEL calculations reveal that the oxygen vacancies were stabilized and transported within the framework of La2Ge2O7 by sharing oxygen and oxygen exchange between the adjacent Ge3O10 chains and GeO4 units, exhibiting a three-dimensional oxide ion transport nature.
研究领域:
无机化学
·
固态离子学
·
功能材料
·
结构化学
·
能源材料
·
晶体化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）